Constitutive model describing hardening behavior under non-proportional cyclic loading

Abstract

The complex multi-axial stress field in various parts of buildings is created during a big earthquake. To evaluate the safety of buildings, the constitutive model with high reproducibility against the complex hardening behavior under the multi-axial stress field has been required. In this study, a constitutive model i s proposed to reproduce the hardening behavior u nder the multi-axial cyclic loading. In particular, we focus on the saturation of stress amplitude and the hardening effect under non-proportional cyclic plasticity. The proposed model is developed based on t he concept of the non-hardening strain region. A few additional parameters are employed and the method for identification of the material constants is proposed for the practicality of the model. The proposed model is validated through the comparison between the numerical and experimental results of the tension-torsion testing.